Watch out, Max and Ruby. Wells's new anthropomorphic heroine, Sophie, is a two-year-old rodent with mischief in her eyes and an inability to stay out of trouble. After getting sent to time-out for unnecessary roughness during dinner with Mama (a mac and cheese dinner ends up on the floor twice) and upsetting the laundry Daddy has folded (also twice), Sophie comes up against a master: Granny. Instead of giving Sophie a time-out for repeated eyeglasses-snatching, Granny gives herself one, moving from the sofa to the rocking chair, where she sits implacably, arms folded. Wells's always sunny drawings get an extra punch from collaged pieces of brightly patterned fabrics, and her characters' facial expressions have plenty to say about parental patience and wild toddler abandon. As wise (and concise) as ever, Wells lets readers have guilt-free fun savoring Sophie's naughtiness, but delivers the story's aha moment with an equally deft hand. Good behavior isn't really about obeisance to the rules, readers will gather. It's about understanding what makes us pleasant to be around. Ages 2–up. Agent: Brenda Bowen, Sanford J. Greenburger Associates. (Jan.)